An overload detection device is installed in a high-lift work vehicle to prevent it from overturning due to a load placed on its work platform that is excessively large relative to the work radius. Japanese Registered Utility Model Gazette No. 2531316 discloses a structure through which the load on the work platform at the front end of the boom is detected by providing a plurality of load cells between the floor frame and the floorboard and adding the values indicated by the detection signals from the load cells.
In addition, Japanese Unexamined Patent Publication No. 1994-18397 discloses a structure achieved by linking the inner section of the telescopic boom and the work platform via a load sensor and also providing a load center between the level cylinder and the work platform to determine the load on the work platform based upon the signals output from the load sensors.